Myocardial ischemia and infarction analysis and detection within ventricular tissue, for example, is used in the management of cardiac disorders and irregularities, which are caused by a lack of blood and oxygen, in heart tissue. Usually, surface ECG signal analysis based on waveform morphology and time domain parameters is utilized for myocardial ischemia and infarction detection and characterization, such as by determination of ST segment or T wave changes (repolarization). However known systems fail to provide a comprehensive quantitative method for myocardial status detection and characterization, such as for severity characterization of an ongoing myocardial ischemia event with chest pain and discomfort. Additionally, known systems for cardiac ischemia and infarction identification and analysis based on ECG signals are typically subjective and need extensive expertise for accurate pathology interpretation and proper cardiac rhythm management.
Coronary Artery Disease (CAD) and heart-related problems and cardiac arrhythmias are severe frequently fatal conditions. A 12-lead electrocardiogram (ECG) and multi-channel intra-cardiac electrogram (ICEG) comprise a diagnostic reference standard used for evaluating cardiac rhythm and events. Known waveform morphology and time domain parameter analysis, such as of a P wave, QRS complex, ST segment and T wave, are used for cardiac arrhythmia monitoring and identification, e.g. of atrial fibrillation (AF), myocardial ischemia (MI) and ventricular tachycardia/fibrillation (VT/VF), for example. However, waveform morphology and time domain parameter analysis are sometimes subjective and time-consuming, and require extensive expertise and clinical experience for accurate interpretation and proper cardiac rhythm management.
Cardiac electrophysiological activities and signals (ECG and ICEG signals) are time varying and known signal analysis typically fails to localize a precise malfunction and identify its severity and an associated trend of cardiac events (e.g. of myocardial ischemia and infarction), such as cardiac pathology irregularity stages and arrhythmia occurrence. Known clinical diagnosis of myocardial ischemia and infarction detection and characterization are based on ST segment voltage deviation for ischemia event detection (e.g. 0.1 mV elevation is a clinical standard for myocardial ischemia (MI) detection). However this standard only works for surface ECG signals, NOT for intra-cardiac electrograms (ICEG signals) and ST segment (voltage) deviation fails to indicate myocardial ischemia severity.
Known systems for myocardial ischemia and infarction analysis typically need a benign signal as a baseline for threshold determination of events and lack reliability, stability and accuracy, especially in emergency cases. Known methods for MI analysis focus on an event which is more qualitative involving detection and evaluation of MI occurrence and lack a capability for quantitative characterization of MI severity. Furthermore, known ischemia event detection systems may cause a false alarm due to reliance on single parameter analysis such as measurement of magnitude of an ST segment. Known medical applications also need improved accuracy and capability for timely detection and characterization of an MI event, which can be used in an ICD (Implantable Cardiac Defibrillator) or a portable system in cardiac applications, such as Holster monitoring. A system according to invention principles addresses these deficiencies and related problems.